From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: To: Ryan Wilkins From: Wolfgang Denk Mime-version: 1.0 Content-type: text/plain; charset=ISO-8859-1 In-reply-to: Your message of "Sun, 24 Oct 2004 18:31:37 EDT." <77988B3D-260C-11D9-BA35-0050E4B0DC64@elevated-networks.com> Date: Mon, 25 Oct 2004 01:39:55 +0200 Sender: wd@denx.de Message-Id: <20041024234000.EADA1C1430@atlas.denx.de> Cc: linuxppc-embedded@ozlabs.com Subject: Re: MPC850 and GDB help List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , In message <77988B3D-260C-11D9-BA35-0050E4B0DC64@elevated-networks.com> you wrote: > Ahh yes.. I wanted to get u-boot loaded into RAM and running from > there. The reason being, I'm having a bit of a hard time writing a > flash chip definition file in the MPCBDM Flash.def format for the Intel > DA28F320J5 flash chip. My thought was to boot u-boot from ram and then > see if it had better luck at detecting my flash chip and then try to > coerce it into writing u-boot to flash for me. This is the wrong approach. First understand the problem, and fix it. You will need exavctly this understanding to be able to port U-Boot. You MUST go step by step. You cannot leapfrog problems. > As for the "running Linux from ram" thing it was another fleeting > thought. Something along the lines of if I can't get u-boot to run > from ram maybe I could get Linux to boot from ram and then go from > there. No, that would even be trying to jump over more than one problem, and is all the more bound to fail. > Answer me this if you would.. Does the MPC850 have some sort eeprom or > parameter RAM on-chip that would be remembered in the event of a hard > reset or power cycle and preclude the chip from booting from flash if > certain registers were changed? No. There is no information kept in the MPC8xx processor itself after power-cycling it. But depending on your hardware there may be features like an EEPROM with VPD or programmable BCSR's or even plain old jumpers. > I'm looking through the manual for the 850 now but don't see anything > jumping out at me. Check the documentation for your _board_. If you have it, that is. [And if you don't, then either give up now or plan for a _lot_ of frustrating experience.] Best regards, Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de Boykottiert Microsoft - Kauft Eure Fenster bei OBI!